Aeroplane landing ski



De c. 27, 1932. MARKEY 1,892,064

AEROPLANE LANDING SKI Filed May 5; 1930 3 Sheets-Sheet l INVENTOR BYQW27, 1932- R. l. MARKEY AEROPLANE LANDING SKI 3 Sheets-Sheet 2 Filed May5, 1930 IN VSNTOR @04 M v ATTORN EYS Dec. 27, 1932. R. l. MARKEYAEROPLANE LANDING SKI Filed May 3, 1930 5 Sheets-Sheet -5 INVENTOR W 3BY f zToRm-ws 2 Patented Dec. 27, 1932 UNITED STATES PATENT orrlcsROSGOE I. MARKEY, OF BUFFALOQNEW YORK, ASSIGNOR TO THE AVIATION PATENTAND RESEARCH CORPORATION, OF 'NEW YORK, N. Y., A CORPORATION OF NEW YORKAEROPLANE LANDING SKI Application filed May 3, 1930. Serial No. 449,401.

This invention relates in general to improvements in aeroplane landinggear and more particularly to pedestals for carrying skis and forattachment to aeroplane axles.

The object of this invention is to provide a unitary ski landing gearconstruction comprising a pedestal with a landing ski attached theretoand provided with its own shockabsorbing units and with suitableconnections for ready attaclnnent to and detachment from the axles ofaeroplanes.

It is a further object of the invention to provide a unitary structureof this type which will not only be readily attached and detached butwhich will allow for relative movement between the ski and the aeroplaneagainst the action of resilient shock-absorbing means.

A further object of the invention is to provide such a constructionwherein the shockabsorbing means will allow for .relative movement ofthe ski'with the aeroplane longitudinally and transversely but which,

will in themselves provide not only for an effective landing device butwill also retain the ski in the proper position free from movement whilethe aeroplane is in flight.- With the foregoing and other objects inview, the invention consists in the combination of parts and in thedetails of construction hereinafter set forth in the followingdescription and in the appended claims, certain embodiments thereofbeing illustrated in the accompanying drawings, in which Q n a o nFigure 1 -1s a dlagrammatlcal View in exterior side elevation showingthe landing gear in flying position.

Figure 2 is a similar view of the landing gear showing the relation ofthe parts of the pedestal upon receiving an impact upon the landing ofthe aeroplane.

Figure 3 is a vertical transverse section taken through the aeroplaneaxle and a portion of the pedestal.

Figure 4 is an elevation in perspective of a modified form of ski andpedestal attached to the axle of an aeroplane.

Figure 5 is a front view in partial vertical section of a ski andpedestal of the type shown in Figure 4.

Referring more particularly to the drawings a ski 8 is providedwith'upstanding lugs 10 on either side of the ski to provide a pivotconnection 11 for the hinged support 1 which at its upper end encirclesthe" axle 9. Surrounding the axle 9 are tubular spacers 6 forpositioning a centrally disposed lug 7.

'The upper tubular portion of the sup ort 1 is provided with inwardlydisposed anges 12, which allowfor a clearance 13 between them and thespacers 6. Cylindrical elements 2 of elastic quality, such as rubber,are centrally apertured and arranged about the spacers 6 so as to fitsnugly between the tubular portion of the support 1, the flanges 12, andthe spacers 6. Axle flanges 15 and 16 are then arranged so as to abutagainst the spacer members 6.

To the axle flange 15 there is rigidl attached an arm 5, by means ofbolts 1 or the like. A shock-absorbing element of the spring or dashpottype 4 has an arm 18 connected to the lower end of the arm 5 by means ofa universal joint as a longitudinal pivot 19 and a transverse pivot 20.The arm 21 ofthe element 4 is connected to the ski by means of auniversal connection.

The, shock-absorbing unit 3 which may be ofthe spring or dashpot typehas an arm 22 connected to the lug 7 by means of a universal joint, theo posite end of the shock-absorbing unit 3 ing pivotally connected tothe lug 23 at the pivot 24, through a univer sal joint.

A clearance 25 is arranged for at the inner and outer end of the tubularportion of the support 1 surrounding the axle and the flange 15 and 16to provide for transverse movement of the support 1 against the actionof the rubber elements 2. This allows for a slight transverse movementof the ski and pedestal assembly with relation to the axle and theaeroplane. The tubular support 1 being essentially a floating member asfar as the axle is concerned is thus rigidly connected to the ski as faras transverse movement is concerned. The support comprising the arm 5and the shock-absorbing unit 4 being attached to the lug 10 which isrigid in its relation'to the ski 8 is necessarily provided withuniversal 'oiuts at its pivotal connections to allow or the transversemovement of the support 1 with relation to the axle. This is also trueof the shock-absorbing unit 3, in that it is connected b means of thearm 22 through a universal oint to the lug 7 which is rigid in itsrelation to the axle.

By means of the above-described construction the entire destal assemblyincludin the ski attached t ereto maybereadily slippe on to the axle andheld in place by means of the ordinary well-known expedients. The pro erangle of disposition of the ski 8 having en determined and shown inFigure 1, the same relation of the ski to the aeroplane will beeflectively maintained under ordinary conditions. However, upon thelanding of an aeroplane the assembly will be subjected to impacts whichare taken care of in a longitudinal plane, as shown in Figure 2, inwhich the shock-absorbing unit 4 is elongated and unit 3 is compressed,each of these movements being resisted by the units themselves.

The support 1 by means of the rubber shock-absorbing elements 2 isadapted to ab- "sorb a considerable portion of the vertical thrustimparted by the impact on landing and any tendency of the ski pedestalto rotate about the axle 9 is effectively resisted by the absorbingunits 3 and 4 due to the impact upon landing. The shock-absorbing units3 and 4 also resist any tendency of rotation of the ski pedestal aboutthe axle 9 caused by thewind while the aeroplane is in flight. v 3

The construction involving the use of the rubber rings 2 is suflicientlyrigid to avoid any vibration or oscillation of the ski while theaeroplane is in flight but will allow for :1 limited relative transversemove grit-of the ski pedestal with relation to the axle in case a sideskid landing is made. This is not only a means of prevention of breakageof parts of the landing gear but also allows for. enough flexibility ofthe construction to eliminate a tendency of the aeroplane to turn oversidewise and damage the wings.

Another form of the invention is shown in Figure 4, in which the axle ofthe aero lane has releasably attached thereto a sliding lock 27 ofrectangular form adapted for sliding movement within a frame 28 formedby four uprights 29 with bracing members 46 which limit the downwardmovement of the block in the frame.

There are also provided four converging braces 40 attached to areinforced portion 32 of the ski, which braces are joined together atthe top by the longitudinal tubes 33 and the transverse tubes 34therebetween'. The central cross tube 44 is adapted to receive aplurality of resilient cords 43 which are wrapped around the bearing andretainer members 45 surrounding the axle 48, thus restraining thedownward movement of the axle and the consequent downward sliding of theblock 27in the frame 28. In order to properly brace the pedestal, thereare rovided diagonal braces 35 and 36 and 37 an 38 between the two mainrear supports and front supports of the pedestals, respectively. Thereare also provided diagonal braces 39 and 39' from the lower portion ofthe rear supports and the uprights 29 and braces 41 and 42 from thebottom of the front supports to he uprights 29.

In attaching the ski tothe axle, the ski is locked by means of thecollar 14 against movement longitudinally of the axle and the relativemovements possible are vertical, rotational and lateral, which movementsare resisted by the shock absorbing elastics. The shock of the return ofthe axle 48 to no-load position after the ski 30 leaves the ground, iscushioned by a pair of resilient blocks 53, of rubber or similarmaterial, which are compressed between the blocks 27 and the lonitudinal members 33. These cushion blocs reduce the noise of operationof the shock absorbing unit and increase the life of the structure byeliminating sudden impact loads which would be produced by the energystored in the rubber cords 43 when elongated and suddenly released.

The position of the shock-absorberinthe ski pedestal unit itself makesfor a quick attachment and detachment. The block 27 fitting in theguideway 28 allows for a rotational .movement of the ski about the axle,but this movement is resisted and controlled by means of theshock-absorbing cords 47, which may be wrapped under tension around tworigid lugs 52 arranged fore and aft with relation to the axle. The skipresents a surface of considerable size and without this precautionarymeans would be caused by the wind to oscillate and render landing adangerous proceeding. The tension and strength of the elastic cords arearranged accordingly. For directional purposes while the ski is on theground, a ski is provided with runners 49 on its bottom surface. Theserunners may be stripped with a non-corrosive metal as brass or stainlesssteel which makes it easier to break the ski loose after it has beenresting on the snow and moreover increases the life of the ski.

Having thus described my invention, I claim:

1. In combination with an aeroplane landing ski, a pedestal comprisingan energy absorbing unit which provides in itself a flexible mountingfor said ski on the supporting axle of said aeroplane, said unitcomprising a support from said axle and 'pivotally connected to said skito resistingly permit the rotation-of said ski about said axle and thevertical and transverse movement of said ski with relation to said axle,a second shock absorbing member having a pivotal connection to said skiat a point in advance of said axle,

said member being rigidly connected to the axle assembly.

2. In combination with an aeroplane landing ski, a pedestal comprisingan energy absorbing unit which provides in itself a flexible mountingfor said ski on the supporting axle of said aeroplane, said unitcomprising a support from said axle and ivotally connected to said skito resisting y permit the rotation of said ski about said axle and thevertical and transverse movement of said ski with relation to said axle,a second shock absorbing member having a pivotal connection to said skiat a point in advance of said axle, said member being rigidly connectedto the axle assembly, a third shock-absorbing member including a supportextending from a rigid connection to said axle assembly and a resilientelement pivotally connected thereto and to said ski.

3. In combination with an aeroplane landing ski, a pedestal comprisingan energy absorbing unit which provides in itself a flexible mountingfor said ski on the supporting axle of said aeroplane, said unit comrising a support from said axle and pivotal y connected to said ski toresistingly permit the rotation of said ski about said axle and thevertical and transverse movement of said ski with relation to said axle,a second shock absorbing member having a pivotal connection to said skiat a point in advance of said axle, said member being rigidly connectedto the axle assembly, a third shock-absorbing member including a supportextending from a rigid connection to said axle assembly and a resilientelement pivotally connected thereto and to said ski, said second andthird means having tension and compression elements which are adapted towork in opposite phase to resist the corresponding opposite action toeach other.

4. In combination with an aeroplane landing ski, a pedestal comprising asupport pivoted to said ski and terminating in a tubular portionsurrounding the axle of said aeroplane, resilient elements disposedaround said axle between the same and said tubular portion to allow forrelative vertical and transverse movement between the ski and said axle,a strut rigidly connected to the inner flange of said axle, said strutcomprising a tension and compression shock-absorbing unit which ispivotally attached to said ski.

5. In combination with an aeroplane landing ski, a pedestal comprising asupport pivoted to said ski and terminating in a tubular unit which ispivotally attached to said ski, another strut universally mounted on alug arranged on said axle centrall with respect to the tubular portionof said first-named support, said last named strut having a tension andcompression shock-absorbing unit pivotally connected thereto andangularly disposed with relation therewith and also pivotally connectedto said ski.

6. In an aeroplane, a landing ggar havingv April, 1930.

ROSCOE I. MARKEY.

portion surrounding the axle of said aero- I plane, resilient elementsdisposed around said axle between the same and said tubular portion toallow for relative vertical and transverse movement between the ski andsaid axle, a strut rigidly connected to the inner flange of said axle,said strut comprisi a tension and compression shock-absorbing

